Add additional details for cm contribution branch extraction to the example

Added some information on the Java program ConvertBuildTagBranchesToGitTags.
Adjust .gitignore to include vim swap files and the Gemfile.lock
Improve documentation with more details
Add images and documentation for several new topics

Added documentation on pulling out a single build tag by explicit fetching
and then how to fuse directly using the fusion-maven-plugin.dat file.

Added some impex information on how it should work with the split impex.

Changed the index.md to include the new fuse a build tag example.